[Spoon]

I developed a course plan & did the geocaching with my JROTC cadets during our annual Summer Leadership program (2 weeks of physical Boot Camp, sports & classroom studies) They had a blast using the little Garmin units. Pretty simple. 60 nautical miles = 1 degree; roughly 69 statute miles = 1 degree. (1.15 statute miles = 1 nautical mile; 6072 ft in nautical mile) Breaking it down from there...that's where the GPS comes in. The civilian units have a sensitivity that will bring you within about 20 feet of the true target. Our Sr. Instructor was a mathmatician that worked on weapons delivery. DOD units can put a cruise missile through your front door from hundreds of miles away! The powers that are/were didn't dare give the public that ability! Since each is different, depending upon which unit is used to establish a course, you may note some discrepancies; be patient and LOOK back to the clues if given. The group of students that ended up with my personal unit had a tiny bit of an edge;the other units belonged to the school district. The lesson plan and power point slides I put together was supposed used and integrated by HQ to develop a nation-wide course so each JRTOC program didn't have to re-invent the wheel. I don't know what ever really happened to the HQ Inspector that requested it for with that intention. I'll try and dig around through my old discs and see if I still have a copy. May not be able to bring it up since it could be on a 3.5" floppy. Those were the days and technologies have morphed at warp speed.

Try one event and see if it provides enough challenge. Really allows for orienteering skills to develop, but can't beat old-fashioned map reading skills. When things go POOF, the old ways will still work! Geological grid map, compass and knowing your stride

 

[Spoon]

Found the GPS Lesson

hombre`, I located the Power Point lesson...here's some excerpts. There are many URLs that can give everyone the details on the world-wide hobby of Geocaching.

Position given in Degrees, Minutes, Seconds
Elevation (feet or meters)
Time (atomic clock)
Degree = 69 statute miles; 60 nautical miles; 117 kilometers
GPS Mathematically Computes: Position; Time
HOW’S IT WORK: Satellites (SVs) Orbit = 12 hrs; Receivers track/lock-onto 4 or more Satellites (24+ available). GPS Nominal Constellation consists of 24 Satellites in 6 Orbital Planes with 4 active satellites in each Plane. Orbital Altitude is a constant 20,200 kilometers, 12,524 statute miles or 10,876 nautical miles

GPS MASTER CONTROL is located @ Schriever Air Force Base, CO (at time I built the lesson)
Master Control station uploads ephemeris (precise orbital data); Clock data to the SVs
SVs send subsets of the orbital ephemeris (data) to GPS receivers over radio signals.
TWO MODES – PPS (Govt. & Military); SPS (Civilian)
PPS ACCURACY - Time (UTC) accuracy 200 nanoseconds
SPS ACCURACY - Time accuracy 340 nanoseconds
A nanosecond (ns or nsec) is one billionth (10-9) of a second and is a common measurement of read or write access time to random access memory (RAM).
For comparison, a millisecond (ms or msec) is one thousandth of a second and is commonly used in measuring the time to read to or write from a hard disk or a CD-ROM player or to measure packet travel time on the Internet.
A microsecond (US or Greek letter mu plus s) is one millionth (10-6) of a second.
A picosecond is one trillionth (10-12) of a second, or one millionth of a microsecond.
A femtosecond is one millionth of a nanosecond or 10-15 of a second and is a measurement sometimes used in laser technology.
Here’s what the Cadets practical exercise consisted of. They had 6 caches to locate and 45 minutes to find them. Had to find the 1st one to get coordinates for the 2nd & so on.
SAR (Search and Rescue)Mission:
1 You must find ______ hidden items around the grounds of AJHS
2 You must work as a TEAM
3 You must find items in order to have subsequent coordinates
4 You have _______ minutes to accomplish
(Lives are at stake!)

Like I said, the Cadets had a blast while they applied classroom knowledge through practical application. There was quite a bit of jockeying for control of the GPS unit and which way to head to arrive at the reading/cache locations they were supposed to find. Not all teams found all 6 and some spent so much time arguing and trying to reckon the coordinates as they changed on the display. It was a great day to be a mentor and observe

 

[Spoon]

The only organization outside of DOD that have that type of voluntary participation is the Civil Air Patrol to my knowledge. EPERBs and triangulation of radio signals is a whole n'other ball game, as would be small hand held ground penetrating units for finding metals and metallic objects. Some of the GPS units and EPERBs are melded into simple units that die-hard trekkers can use to keep the folks back home informed of their location(s) while hiking wilderness areas. Heck, even runners have small units that have apps that will tie into facebook and you can watch the map as your friend jogs or runs along the streets, paths and roads...in "real time". That stuff's getting out of control.